The present invention generally relates to semiconductor devices and methods of producing the same, and more particularly to a semiconductor device which is made up of a semiconductor device body and a ring part which holds the semiconductor device body, and to a method of producing such a semiconductor device.
Recently, the integration density of semiconductor devices has improved considerably. On the other hand, there are demands to reduce the size of semiconductor devices. As a result, leads of the semiconductor devices are being arranged at extremely small intervals, that is, extremely narrow pitch.
The strength of the leads deteriorates if the pitch of the leads becomes narrow. For this reason, if the leads are deformed by an external force when the semiconductor device is transported, a short-circuit may be generated by the deformed leads thereby deteriorating the reliability of the semiconductor device.
For this reason, semiconductor devices having the a mold carrier ring (MCR) have been proposed. According to a semiconductor device employing the MCR, a ring which holds the semiconductor device surrounds the semiconductor device so as to prevent the deformation of the leads.
FIG. 1 shows an example of a conventional semiconductor device employing an MCR. A semiconductor device 1 shown in FIG. 1 is generally made up of a semiconductor device body 2 and a ring part 3. This semiconductor device 1 is transported from a semiconductor device producing factory to a destination in the state shown in FIG. 1, that is, in a state where the ring part 3 is not yet removed from the semiconductor device body 2.
The semiconductor device body 2 includes a semiconductor chip (not shown) which is encapsulated within a resin package 4, and a plurality of leads 5 which extend outwardly from the peripheral parts of the resin package 4. On the other hand, the ring part 3 has a frame shape which surrounds the semiconductor device body 2. The ring part 3 is also made of a resin.
The tip end of each lead 5 which extends outwardly from the resin package 4 is embedded in the ring part 3. Hence, the semiconductor device body 2 is supported by the ring part 3 via the leads 5. Further, since the leads 5 penetrate the ring part 3 and are exposed at the outer peripheral part of the ring part 3, it is possible to test the characteristics of the semiconductor device body 2 via the exposed leads 5.
Because the tip ends of the leads 5 are embedded in the ring part 3 and the semiconductor device body 2 is held by the ring part 3 via the leads 5, it is possible to prevent deformation of the leads 5 even if an external force is applied on the ring part 3. For this reason, it is possible to prevent the leads 5 from becoming short-circuited even if the leads 5 are arranged at a narrow pitch, and it is also possible to maintain the leads 5 flat.
Therefore, according to such a conventional semiconductor device 1 employing an MCR, the semiconductor device body 2 and the ring part 3 are independent parts, and the semiconductor device body 2 and the ring part 3 are connected via the leads 5. In addition, the semiconductor device 1 is transported in a state where the ring part 3 is attached so as to prevent deformation of the leads 5. The ring part 3 is disconnected from the semiconductor device body 2 at the destination where the semiconductor device body 2 is actually mounted on electronic equipment or the like.
For this reason, there has been a problem in that the destination must be equipped with an apparatus for removing the ring part 3 from the semiconductor device body 2. More particularly, the destination must be equipped with a lead cutting apparatus for cutting the leads 5 at a predetermined position. This lead cutting apparatus must be able to cut the leads 5 which are arranged at a predetermined narrow pitch without deforming the leads 5 and maintaining the predetermined narrow pitch. However, a lead cutting apparatus which can satisfy such demands is expensive, and there has been a problem in that it is difficult to actually equip each destination of the semiconductor device 1 with such an expensive lead cutting apparatus.